Method of and apparatus for producing carbon black



March 21, 1933.. D YJ. BEAVER 1,902,753

METHOD oF AND APPARATUS FOR vPRODUCING CARBON BLACK original Filed sept.12 1927 l l Q v i 'I 'I N v vwefntoz A d5 n DAV/D f BEA VER PatentedMar. 21, 1933 UNITED STATES PATENT oFFlcE.

nAvm-J. BEAVER., or miznE'rm-Nnw .'rnaamr,l AssIG'Nonmo om A'rLAs cAn-:sonl conm, or nom DELAWARE, A oonronA'rIoN or DELAWARE muon or ANDArrAnA'rUs Fon PBoDUcINe cAnnoN BLACK continuation of nppuontion sonalNo. 219.152, nieu september is, 1927. This application 'mod January Thepresent invention relates to the art of producing carbon. black;` andthis appli cation is a continuation of applicants copending application,Serial No.` 219,152, filed Sept. 12, 1927, relating to method of andapparatus for producing carbon black. .Y Y

In the present industrial production of carbon black from'hydrocarbons,two methods are in large'scale use; namely, incomplete combustion andthermal decomposition. The first method is so well known thatl is needsno description. The second method comprises cracking a hydrocarbon tocarbon black by passing the hydrocarbon through hot checker work or hotretorts or the like. Inthe first method, although the carbon blackobtained is fof good color value and of. excellent physical properties,the yield is very low, amounting in commercial plants known to us toabout 31/2% of the carbon present .in the natural gas. In the secondmethod, the yields arev very much higher and may be as much as 25%, butthe "35 color value of the black is only about 15% of that produced byincomplete combustion and the other physical properties of thermallyproduced black are unsatisfactory from the standpoint of many of itsmost important uses. .It has been considered by many authorities that.the undesirable properties of the carbon black produced by thermaldecomposition are due to the high temperature at which the decompositionof the gas is carried out. However, experiments carried out here haveshown very conclusively that this poor color is due to cracking incontact with hot surfaces (either liquid or solid) and not to the hightemperature. For example, when natural gas is cracked in contact withnickel as a .catalyst at temperatures of 50()o or 900 C., the black hasthe same color, namely '15% of standard, in both cases. It is evidentfrom the results of said experiments that, in order to produce a blackwith satisfactory properties, the decomposition of the hydrocarbon musttake place out` of contact with any solid or liquid surface.

The present invention consists in the combination of steps in theproduction of carbon Serial No. 511,640.

blackV by partial combustion or by decompo- `sition of the gas bycontact with a hot 'gas and in the arrangementand` combination of partsfor producing carbon black by partial `combustion or hot gasdecomposition as 55 hereinafter described and particularly pointed outin the claims.

'The present invention is based on the results of extensive experimentscarried out to find the optimum Vconditions for maximum production ofcarbon ofsatisfactory physical properties by partial combustion ofhydrocarbon or by hot gas decomposition thereof, but more particularlyyby partial combustion of the hydrocarbon.

By suitable design of apparatus and careful adjustment and control ofoperating con- `ditions it is possible to produce by the incompletecombustion of natural gas or other hydrocarbon or hydrocarbon containinggas, l0 yields and eiiiciencies higher even than those obtained by theso-called thermal decomposition processes.

In the drawing forming part of this specification, I have illustratedspecific form of 76 apparatus adapted for carrying out the preferredmethod of the present invention.

Fig. 1 is an elevation of` a carbon black furnace parts being shown insection and parts being broken 4away for purposes of 80 illustration.

Fig. 2 is a section of the furnace taken on the line 2-2 of Fig. llooking in the direction of the arrows, parts being broken away forpurposes of illustration.

Fig. 3 is a section of the furnace taken on the line 3--3 of Fig. 1looking in the direction of the arrows. v

Referring to the drawing, 10 is a furnace preferably provided with innerrefractory lining 11 and an insulating wall 12 for preventing loss ofheat from the furnace, thus rendering it free from atmosphericdisturbance. Gas is introduced into the furnace 10 through a pipe 14. Ingeneral, gas in the pipe 14 will be under pressure and it is preferredto regulate the'fiow of gas to the combustion chamber at a point prior"to its admission thereto. For this purpose, a

valve 16 is illustrated in the pipe '14: outside 109 Y I of the furnace10. A` How meter (not throug shown) may be connected into pipe 14 toassist the operatives in maintaining the desired ratio of gas and air.Pipe 14 extends h the wall of the furnace and into the lowerl part ofthe furnace. Within the furnace pipe 14 is enclosed for most of its lenh in a horizontal duct 20, duct exten ing almost the entire length ofthe furf 1 nace in the direction of the pipe 14. The

duct 20 forms a part 'of\the gas burner apparatus according to thepresent invention and may be convenientl made in the form of arectangular-box as illustrated in Fi 2. Within the conduit 20, pipe 14is notc ed or slotted as indicated at 22 to permit as to pass from ipe14 'into the interior o conduit `20. S ots 22 are distributed evenly orluniformly along the upper side of pipe 14,

' width is almost equal to that of the furnace in the form of thinsheets.

10, the space between adjacent (gas ducts 24 and that between the edgesof ucts 24 and the wall 11 serving as'air ducts26, 26 surrounding thegas ducts 24 and distributing air for combustion equally thereto. Itwill be seen that the air streams and gas streams zare thus given aparallelor stream line flow before they come into contact.

The gas ducts 24 extend upwardly within the furnace chamber, havingmouths 28 through which the gas discharges upwardly It will beunderstood that when the apparatus is in operation flame sheets extendupwardly from the mouths 28. The flame fronts in which completecombustion to C()2 and H2O oc- `curs occupy the positions indicated bydotted lines in Fig. 1. It will be seen that the fiame fronts fromadjacent burners eventuallyv intersect or impinge at their upper ends,whereby passa e of uncombned oxygen beyond the flame ronts is prevented.Burning of free carbon particles by free oxy en is thereby minimized 'orprevented. In t e arrangement. illustrated vall of the ducts 24 have thesame form and size. It

has been found that the ends of the ducts 24 adjacent the mouths becomequite hot and that ordinary sheet steel deteriorates very rapidly atthese points. Burner tips 30, 30 of chrome-iron or like high temperaturealloy may be used at the ends of the ducts 24 in contact with the flameswhich are durable Vand .bon dioxideand water vapor.

under the conditions encountered in practice. Alloy tips 30 may be`secured to the bodies of the ducts 24 by an suitable means, but it hasbeen found pre erable to attach the .tips to the ducts bysuitable'sockets as indic2ated by the lines 32e-32 in Figs. 1

An important feature of the invention consists in the control of partialcombustion of the gas used in making carbon black so that a uniform thinflame front lis formed and maintained around the hydrocarbon gas movingin stream line non-turbulent flow, to supply the heat for decomposingthe hydrocarbon within the'fiame front as the gas diffuses from thecenter of the gas stream out to the flame front during such stream linemovement of the flowing contiguous gas and air istreams. In order tosecure the highest practicable yield of carbon black from the gas theinvention also consists in providin the longest practicable flameperipher or a predetermined cross section area o the gas stream, inorder to vgive the maximum useful energy available for decomposing thegas with radiant heat energy which is radiated from one side of theflame front to the other. Accordingly,

the gas is introduced into the furnace in spaced sheets through burnerducts which vare very wide and relatively thin. The said width of thegas duct has little or no effect on the yield or character yof the gasblack made, but the thickness of the gas duct has to be accuratelycontrolled in order to provide the proper character of the flame frontso as to produce as small amounts as possible of carbon monoxide andhydrogen.

The gas ducts are so arranged that as the gas ldiffuses into the airmoving along in contact with it, a ame front will be formed at thepoints of contact of the gas and air streams or sheets, along whichflame front the gas eventually will be substantially completely burned.In thecase of methane and air the products of combustion will be car- Ifthe gas ducts are too thin, an ideal flame front cannot-bel developedandl com aratively high percentages of hydrogen an carbon monoxide willbe formed on the Yinside of the flame front and thus the yield of carbonblack will be cut down. The hot gas in the flame front has acomparatively `high viscosity, andthe carbon formed by the heat of theflame front on the inside thereof by the def composition of the gas issubstantially all held against the inner face of the viscous flame frontor gaseous sheath and passes upwardly through the furnace chamber in adefinite or non-turbulent flow' of streamline character. This carbonstream does not readily pass or diffuse through the viscous gas flamefront to come into contact with the oxygen due to the maintenance of thesaid streamline flow, which is facilitated by the high temperatureof thefurnace interior.

and the respective 'rates of flow of the gas and air sheets'v orstreams, andtherefore a comparatively small Vamount of the carbon isoxidized to formcarbon oxides.

.D Preferably the :gas ducts should not be less than 3/8 of an linch inthickness and the optimum `results are obtained with a gas duct-of aboutone-halfvinchthiclme'ss. The yields and properties or characteristics ofthe asv black are not affected by increas- ,l ing t e thickness of theduct to one inch or there is a greater tendency for the forma-l tion ofcarbon onthe outlets of the duct tips and this carbon formationseriously interferes with the process and the character ofr the blackbeing manufactured.

' Experiments have shown also that the relative thickness of the airduct to the gas duct is an important factor in determining the yieldsand properties of the carbon black produced. For example, when usingnatural gas, it has been found that the best yield and properties ofblack are obtained when the air duct is 3% times as thick as the gasduct. The minimum thicknessof air duct according to the presentinvention should not be less than 21/2 times the thickness ot' the gasduct. It was found. that when the ratio ofthe thicknesses of the air togas ducts was decreased to 2 the yield was only 1/3 of that when thisratio is 31/2, and further the lower ratio relation produces largeamounts of intermediate decomposition products. It has been found thatthe optimum ratio of the thicknesses of air to gas ducts increases asthe percentage of combustion of the hydrocarbon increases. The optimumratio of 31/2 between the thickness of air duct to gas duct wasdetermined lwhen burning approximately of the methane or natural gas.The optimum ratio of thickness of air duct to gas duct'is, however,affected by the hydrocarbon being burned as well as by the percentage ofcombustion of the hydrocarbon. When using pure ethane in place ofnatural gas, it was foundthat the thickness of the air duct for optimumproduction of black was about six times the thickness of the gas ductinstead of 31/2 as with natural gas. When using ordinary natural gas ofa heating value of between 1000 and 1200 B. t. u., per cubic foot, the

maximum desirable ratio of air duct areav to gas duct area is 7. Forpure ethane having a heating per cubic foot, the maximum desirable ratioof the area of air duct to gas duct is between .91/2'and 10..I .A f vWhen the air contains enough oxygen for v flame taken value of about1790 B. t. u., l

dinar? gas ucts and air ducts produce relative velocities of gas to airin the ratio of 1 to 1.2. At the `.same per cent of combustion thisratio should not be permitted to fall below that of`1 to 2.2 or to riseabove 1 to 0.67, whlle relative velocities of the air and gas streamsgiving velocity ratios of between 2. and 0.9 are more locities ofgas'and air outside of this r e of ratios tend to produce turbulence-`in t e fluid streams, whlch in turnmaterially reduces the yield ofcarbon black and renders the same variable.

Experiments have shown also v'that the yield and properties of carbonblackformed are influenced by the ratio ofgthe flame yfront periphery toarea of gas duct. Under :the best conditions ofoperation V-it hars'been`found that the ratio of the periphery of the transversely at oradjacent the gas duct outletto the area of the gas stream or duct atsuch 'point lies between 2.0 and ,4.5. The preferred ratio is about 4.0.This ratio, however, should not fall below 1% according to the presentinvention and preferably should not be increased above 5.

The air'for supporting combustion may be introduced into the ducts 26 inany con; venient manner within the present invention. In the arrangementillustrated, air is introduced into the furnace 10 below the level ofpipe 14. For this purposea pipe 34 is passed through the wall of thefurnace 10 near its bottom, pipe 34 being illustrated as having a damper36 therein to regulate the vflow of air. A flow meter' (not shown) maybe connected into pipe 34 to assist the operatives in maintaining thedesired flow o air. the furnace chamber below the pipe 14 and'is-slotted or notched as indicated at 38, 38 to discharge-air uniformlyalong its upper face. If desired, the air from plpe 34 mayl be preheatedbefore being used to support combustion in the furnace l0 and for thispurpose I have illustrated a series of heating tubes 40,' 40 extendinghorizontally through two opposite sides of furnace 10 andconvenientlyarranged to run in vertical planes at right angles to the plane of pipes14 and 34. Pipes 40 lie above pipe 34 and maybe heated by any convenientmeans so as to heat the air from pipe 34 as it rises around them. In thearrangement illustrated, gas burners 42, 42 are arranged, one in each ofpipes 40 for heating them internally. The air introduced into thefurnace chamber 10 may be initially under pressure or it may be drawnthrough the apparatus by induced draft. In either case, the ratio of gasto air is regulated by the valve-16 and the damper 36 as desired.

A `Experiments have shown that increasing suitable, since relative .ve-

Pipe 34 preferably extends across.

the complete-combustion of only 60% of or? I natural gas lthe preferredareas -of bon black is practically the color and then The optimumresults as to color value and properties of the black are obtained whenthe ratio of air to gas is that required for theoretically completecombustion of approximately 65% of the hydrocarbon and properties of theblack are almost the same at rates of air based on theoreticallycomplete combustion of between60 and 65% of the h drocarbon used. Withthis per cent of com ustion the optimum thickness of air duct is, formethane or ordinary natural gas, about 31/2 times that of the gas ductas pointed out previously. Y

When the combustion chamber is properly insulated against heat loss, theyiel of carconstant between 45% and 75% combustion of the hydrocarbonused, although the yield orl properties may be slightly adverselyaffected at either extreme of this range. The yield of carbon black isconsiderably decreased when these limits are exceeded in eitherdirection. It is evident, therefore, that the maximum yield of the bestgrade of black is obtained when operating at rates of combustion between60 and 65%. However, decreasing the ratio of air to gas increases the B.t. u., er unit of flue gas leaving the furnace cham er and thereforeincreases its value as fuel. Under certain conditions, it is thereforedesirable to sacrifice some values of the carbon black in order toincrease the value of the flue gas. o

The yield of carbon black from a given amount of hydrocarbon increasesas the temperature of the combustion chamber increases up to the maximumtemperatures investigated. However,

some-of the physical properties of the black may be somewhat poorer ifthe temperature is too high, the best operating temperature being in theneighborhood of 1300-1400 C. Thetemerature of the reaction chamber justreerred to is determined by means of thermocouples placed flush with theinside of the wall of the furnace. However, the temperature observed atthis point is not the only criterion of the effective decompositionenergy available for the production of carbon from hydrocarbons. As isWell known the actual flame temperature of a hydrocarbon, such asmethane, burned in air is over 1800 C1., and, therefore, the percentageof radiant energy from such a ame is very high. If flames of thischaracter are surrounded by relatively cold walls (130() to 1400o C.)this radiant energy would be absorbed very rapidly by the walls and theaverage temperature of the flame will be equal to its surroundings. Itis possible to utilize this radiant energy effectively by so arrangingthe burners that the largest possible surface of any numerousexperiments on singl tiple burner furnaces, that the formation of carbonblack within the dame is activated b direct radiation from other dames.Soli surfaces intervening between` the flames or.-

reiiecting to one fiame the radiation from another, ap ear to absorbthis activatin radiation. n the arrangement illustrate this result isaccomplished by means of a multiple burner unit, the gas ducts havingthe burner tips 30 therein extending parallel flame radiates to anotherflame and not to a wall'. In other wordsz it appears frontv e versusmuly With a single rectangular `b-urner'having I proportionsapproximately the same as one of those illustrated in the drawing, theyield of carbon obtained was 17% of the available carbon in thehydrocarbon gas when the temperature of the reaction chamber was 1150C., measured at the furnace wall. With a 5 burner furnace, the yield ofcarbon was 24% of the available carbon in the hydrocarbon gas, thetemperature and other conditions being approximately the same. Inanother experiment on a multiple burner furnace in which each burner,was surrounded by a thin wall silica tube, the removal of the silicatubes caused the yield to rise from 19.5 to 21% although all temperatureand other operating conditions were absolutely constant. It is evidentfrom the examples just given that the factor of radiation is highlyimportant for'the production of the highest yield of carbon black, andit is preferred that the radiation from fiame to ame beat least fivetimes that from the flames to the walls of the furnace and a ratio ashigh as permissible by the given type of burners used is desirable.

The gases of combustion containing the carbon black formed inthe furnacechamber pass out therefrom at the top through the opening 44 and stack46. The stack structure ordinarily is such that the gases begin to coolrapidly as soon as they leave the furnace chamber. The carbon blackformed, therefore, is in contact with highly heated products of burnertips 30 to the stack 46. Experiments have shown that the time of Contactbetween the carbon formed by the decomposition of the hydrocarbon andthe hot gases influences the yield very largely. The effect ofthe timeof contact-will be apparent from the following example:

combustion while passing from In a series of runs using natural as thevelocity of the gases throughthe urnace was maintained such that thecarbon black .was in contact with the hot gases for a period of twoseconds. In this run the yield of carton black was 26% of thetheoretical. In a second series of runs the velocity of flow of thegases was increased s'o that the time of contact between the carbonblack and the hot gases in the furnace was decreased to -one second, theyield of carb-on black being thereby increased to 33% of thetheoretical. This decrease in yield with increased time of contact isdue presumably to the reaction of the carbon with the carbon dioxide andthe water vapor in the gaseous products of combustion. However, it wasfound that the time of contact cannot be decreased beyond a certainamount since it is essential to prevent decomposition of any appreciableamount of hydrocarbon by impinging on .the hot walls of the reactionchamber. As above mentioned, carbon formed in contact with the hot wallsis of a very poor grade and therefore contaminates and lowersthe gradeof the carbon formed within the gas when the two are mixed together.Therefore, the optimum conditions for operation is one in which the timeof contact isY reduced to a minimum consistent with production of carbonblack entirely within the gas stream Without decomposition of anyhydrocarbon on the walls of the furnace. In operating a furnace, the topof which was 86 inches above the burner tips, it was found that due tothe maintenance of streamline conditions of fluid flow Within the same,the minimum time of contact that could be used and still obtain a goodgrade of carbon black was about one second when burning natural gas at(S0-65% combustion with the optimum thickness of gas and air ducts.However, this time can be decreased somewhat by increasing the per centof combustion because under these conditions the iiame is shorter thanat the lower per cent of combustion. In extended large scale tests,under proper conditions, the time of contact was reduced to 1/2 secondwhile still obtaining a good quality of black. Therefore, the optimumrate. of absolute velocity o-f flow of gas and air is controlled largelyby the height of the furnace since this height determines the time ofcontact when using a given type of burner. However, as above mentioned,the higher the temperature of the reaction chamber, the higher the lossof carbon. the yield obtained with` a Contact of `one second between hotgases and 'carbon black is dependent on the temperature ofthe reactionchamber. As was pointed out above, increased temperature of the reactionchamber increases the yield of black and it also increases the loss ofblack by reaction With In other words,

the flue gas. In order, therefore to obtain maximum yields it has beenfound desirable to make the time contact as short as possible and thetemperature as high as is consistent with the type of apparatus used.

As the reaction between the carbon black and the hot furnace gases isrelatively slow as compared to the speed of the initial formation of theblack, the time of contact between the carbon black and the hot gaseswithin the furnace chamber may be extended materiallyabove one second. Acontact period of three seconds is the greatest len h of timewhichappears to give good resu ts.

The construction and method of operation of the apparatus previouslydescribed will be evident to those skilled in the art from the foregoingdescription. For purposes of convenience, however, the apparatus and itsmethod of operation. according to the present invention may be brieflyvdescribed as follows:

The apparatus consists essentially of a furnace or reaction chamber,preferably arranged verticall and surrounded with suitable heat insuating material to prevent heat losses. The furnace chamber is ingeneral, lined with suitable refractory material and contains in itslower section a suitable arrangement of gas supply ducts,

air supply ducts and burners, the shape and dimensions of the furnace,gas and air ducts, and burners, being governed b the conditions setforth below. Each urnace contains a plurality of burners and preferablya considerable number so arranged that the flames radiate mainly to eachother, which in conjunction with the fact that the whole furnace isinsulated from heat loss, produces high temperatures within the flamesand promotes the interchange from flame to ame of those activeradiations which promote the decomposition of the carbon-containing orhydrocarbon gas to form carbon black. These burners may be rectangularin cross-section and arranged in parallel rows as illustrated, butvarious shapes and arrangements of the burners may be used within thepresent invention. Whatever the size and shape of theindividual burners,they must be so arranged that the ratio of total transversecross-sectional perimeter (flame front) adjacent the burner outlet tototal cross-sectional area (gas duct area) at this point lies between 1%and `5 and preferably between 2.0 and 4.5. The spacing of the burners,or in other words, the area of the air duct between them, must be suchthat the ratio of air duct area to gas duct area lies between 21/2 and 7while using ordinary natural gas, of a heating value of from 1000 to1200 B. t. u. per cubic foot. The preferred ratio of air duct area togas duct area for ordinary natural gas is aproximately 3.5. If acarbon-containing gas of highlen er or lower heating value is used, theratio of air duct area to gas duct area should be changedcorrespondingly to the increased or decreased amount of air re uired toobtaln the same percentage of tota combustionpf the gas, or, in otherwords, so as to maintain the same ratioof the linear velocities of airand gas as is 'ven by an a1r duct/ gas duct area ratio o between 21/2and7 1n the case of natural gas of the heating value above stated.Decreasing this area ratio materially, soon adversely affects the ieldsand properties of y the product. igher ratios (lower relative airvelocities) can be used wlthout materially adverse effects so far as themethod and product is concerned but it is disadvantageous to use suchhigh ratios in practice since they increase the size of the furnace perunit of production capacity. The optimum air duct/gas duct area ratio isfurther conditional in some degree on the use of the preferred airsupply of (S0-65% of that needed for the total combustion of the gas. Itis not necessary -to restrict the air supply to narrow limits, however,since an air sup ly within the range 'of 40-7 5% of that nee ed fortotal combustion of the gas gives yields which are a great improvementover resent operation practice. If air be supphed in otherthan thepreferred amount stated (G0-65% of that required for total combustion)thel air duct/gas duct area ratio should preferably be changed in thesame pro ortion so as to maintain the same ratio of inear velocities ofair and gas. The size and shape of the furnace or reaction chambershould be such that the time lof contact ofthe furnace gases in the hotzone of the furnace is within the limits 0.5-3.0 seconds, the preferredlimits being, however, 0.5-1.0 second. At

lower times of contact than 0.5 second, the properties of the productare adversely affected while for times of contact of over 1.0 second,the yield of product tendswith the hot furnace gases after its initialformation in the ames, this reaction being however, relatively slow ascompared to the speed of its initial formation. The hot zone of thefurnace in which reaction occurs between the highly heated gases and thecarbon black is herein understood to comprise the volume of the furnacebetween the level of the burner tips and the furnace offtake where thecooling of the gases first becomes rapid.

While I have described herein a given form of apparatus and a givenmethod of operation, it will be understood that I do not limit myself todetails of the foregoing description, the invention being limited anddefined solely by the terms of the appended claims. In particular, itwill be understood that we prefer not to collect the carbon black oncold surfaces, or otherwise t0 cool the furnace chamber, and thatcircular burners and air ducts may be used instead of rectangular ones.y In the specilication and claims the values iven for the relationship.betweenthe perimeter of the ducts or flame fronts and thecross-sectional areas of the ducts or flame fronts are those whichobtain when using the latter, the said arrangement of the air and gasducts within the furnace chamber thereby providing for the radiationdirectly from each flame to the others of a greater proportion ofradiant ener during the combustion of gas in the c amber than isradiated from such iame directly to the walls of the chamber. v

2. Apparatus for the production of carbon black, comprising aheat-insulated furnace chamber having its interior free from collectingsurfaces interfering with the free iow of fluids .therethrough aplurality of spaced, attened burners 'sposed within said chamber withtheir longer sides respectively parallel, and means for introducin airinto the said chamber around each o the burners, the said meansproviding a total transverse cross-sectional area available for air flowgreater than that of the total transverse cross-sectional area' of thesaid plurality of burners, the said-arrangement of the burners providingfor the radiation directly from one ame to adjacent flames of a muchgreater proportion of its radiant energy than is radiated directly fromsuch flame to the walls of the furnace chamber. l

3. Ap aratus for the production of carbon blac comprising, an insulatedfurnace chamber, a plurality of thin gas ducts disposed in parallel inthe lower portion of the chamber and accurately spaced to providetherebetween a plurality of air ducts, each of the latter beingsubstantially wider than the intermediate gas duct, the tota-ltransverse area of the air ducts bearing a preselected proportionalrelation greater than unity to the total transverse area of the said gasducts at their outlet ends, means for introducing air into the lowerportion of the furnace chamber, means for distributing the bon black,comprising a furnace chamber containing in its lower portion a pluralltyof flattened ,burnersV disposed adjacent each other with their fiattenedsides arranged v substantially in parallel planes and extendingsubstantially the entire width of the furnace chamber, eachof the saidburners having a mouth of between 3/8" and 1 in thickness, means forowing air4 u wardly throughthe furnace and around eac of the said spacedburners, the ratio of the spacing between adjacent burners to thethickness of each burner mouth beingV within` the range of from 2.5:1 to7: 1.

5. Apparatus for the production of carbon black, comprising a furnacechamber, a plurality of spaced flattened burners arranged in the saidyfurnace adjacent each other with the longer sides thereof parallel,each of the said burners having at its outlet end a transversecross-sectional perimeter between 2 and 4.5 times its cross-sectionalarea at the said outlet end, and flattened air ducts interposedbetweenvthe respective gas ducts and surrounding each thereof, the totaltransverse cross-sectional area of the air ducts being greater than thetotal transverse area of the burners.

6. An apparatus for the production of carbon black from hydrocarbon bypartial combustion, comprising a furnace chamber, a plurality ofparallel relatively narrow gas burners in said chamber and wider butelongated air duets surrounding said burners and distributing airequally thereto.

7. An apparatus for the productionl of carbon black from hydrocarbon bypartial combustion, comprising a furnace chamber, and a plurality ofparallel burners positioned within said chamber in uniformly spacedrelation, the ratio of the total crosssectional perimeter of saidburners at their outlet end to their total inner cross-sectional areaadjacent the said ends lying between 11/2 and 5, means for iowing airthrough the chamber and around each of the saidv vspaced burners, thespacing between adjacent burners bearing a ratio tothe inner thicknessof the individual burner duct of from 2.5:1 to 7:1. n

p 8. In the process of producing carbon black by the partial oxidationof hydrocarbons in an unobstructed, enclosed space, the

improvement comprising flowing a plurality of flattened alternatestreams of airv and hydrocarbon gas at pretertermined velocities in thesame direction through the said space, burning the said gases withbetween 40% and 75% of the theoretical amounts of air required for thecomplete combustion yof the said gas, and maintaining the relative gasintro-v and ifV velocities of the i respective 2.2 and streams within`the ratios 0F51: 1:.6.

9. In the process of producing; carbon l bonsin anunobstructed,enclosedchamber, l

the yimprovement:comprising fiowing alter-v nate streams of air andhydrocarbon gas at predetermined velocities inthe same directionthroughthe chamber,-burning the said gases with between 40% vand 75% of thetheoretical amounts' of air required for the complete combustion of thegas, and maintaining the relative velocities of the respective gas andair streams within the ratios of 1: 2 and 1: .9.

10. .In the process of producing carbon black by the partial oxidationof hydrocarbons in a heated, enclosed chamber, the improvementcomprising fiowin a plurality of alternatestreams of air-an hydrocarbongas at predetermined velocities in the same f direction through thechamber, burning the said gas with between 40% and 75% of theVtheoretical amounts of air required lfor the complete combustion of thegas, and maintaining the relative .velocities of the respective gasv andair streams approximately in the ratioA of 1: 1.2.

11. In the art of producing carbon black by the partial oxidation ofcontiguous iowing streams of hydrocarbons and air in a heated, Ienclosedchamber, the im rovement comprising lburning the said hy rocarbons withbetween 40% and 75% of the theoretical amountof air required for thecomplete combustion of the hydrocarbon.

12. In the art of producing carbon black by partial combustion ofcontiguous iowing streams of hydrocarbons and air in a heated, enclosedchamber, the improvement comprising burning the said h drocarbon withbetween 60% and 65% o the theoretical amount of air required for thecomplete combustion of the hydrocarbons. 13. In the art of formingcarbon black by decomposition of hydrocarbon in the gaseous phase and inthe absence of cooling plates the improvement comprising limiting thetime of contact of carbon formed from the hydrocarbon with highly heatedgases of combustion tobetween l and 3 seconds, while out of contact withsolid cooling surfaces, and thereafter rapidly cooling the gaseousreaction products containing the carbon black.

14. In the art of forming carbon black by partial combustion and in theabsence of cooling plates, the improvement comprising limiting the timeof contact of carbon formed lfrom hydrocarbon with highly heated gasesof combustion to not more than one second while out of .contact withsolid coolfing surfaces andl .thereafter rapidly cooling blackby'thepartial oxidation of hydrocar- 7 carbon black. v

15. The method of making carbon black comprising flowing into a heated,enclosed space, a plurality of narrow streams containing a gaseoushydrocarbon, each of the said streams having its transverse' major axisparallel to adjacent streams at its point of entry into the enclosedspace, burning the respective streams of h drocarbon in a surroundingatmosphere oair, the latter being present 1n amounts insufficient toermit the complete combustion of the hy rocarbon, directly radiatin themajor portion of the radiant energy rom each of the resultant llames toadjacent dames, thereby decompos-A ing the unburned portion of saidhydrocarbons to produce carbon black substantially out of contact withsolid or liquid surfaces.

16. The method of making carbon black comprisin burnin hydrocarbon in aplurality of ames of determinate shape with a supply of oxygensuflicient for the complete com ustion of a portion only of saidhydrocarbon and maintainin the shape and location of each of the saillames so that each `flame presents the maximum amount of by partialcombustion of hydrocarbon, com-v prising decomposing a. portion of thegas to l'so form carbon black while the gas is flowing in a plurality ofspaced thin flat streams each surrounded by a flame front in whichcomplete combustion of another portion of the gas occurs, maintainingthe combustion within an insulated chamber to conserve the heat' and toradiate heat from one llame front and the walls to another, andpreventing the diffusion of the carbon black through the viscous flamefronts until the gases of combustion have passed into a zonesuiiiciently cool to retard the combustion of the carbon. f

18? An apparatus for the production of carbon black by partialcombustion of hy'- drocarbon comprising a furnace having a lurality ofrelatively narrow burners t erein, and arranged with their major axesparallel, the outlet end of each burnerl havingl an effective thicknessof between 9/8 to 1 inch and having inside transverse cross-sectionalperimeters adjacent their outlet ends between 2.0 and 4.5 times theircross-sectional areas at the said ends.

19. In the art of forming carbon black by a partial combustion ofhydrocarbon, the

improvement comprisin burning hydrocarbon of from 1000 to 1 90 B. t. u.per cu. ft. in a heated, enclosed space in a gas stream by oxygen in anair stream flowing in contact therewith while limiting the combustion tobetween 40% and 7 5% of the hydrocarbon and making the area of the air voreticall stream as it enters the enclosed space fromA two land one halfto ten times the area of the gas stream. v 20. In the art of formingcarbon black, the improvement comprising burning hydrocarbon of from1000 to 1200 B. t. u. per cubic foot in a-heated, enclosed space in agas stream by oxygen in an air stream lowing in contact therewith whilelimiting the combustion 'to between 60% and 7 0% of the hydrocarbon andmakin the area lof the air stream adjacent the point of entry of the gasstream into the enclosed space from three to four times that of the gasstream as it enters the enclosed space, and maintaining heat insulatingconditions in the zone of combustion.

21. In the art of vmaking carbon black by the partiall combustion ofhydrocarbon, the improvement comprising burning hydrocarbon of from 1000to 1200 B. t. u. per cubic foot in a plurality of relatively vnarrowllames each arranged to radiate a major proportion of their radiantenergy directly to others of the flames, supplying air unlformly to saidflames, and limiting the combustion to between and 70% of thehydrocarbon.

22. In the improvement set out in 'claim' 21, maintaining heatinsulating conditions in the zone of combustion. 4

23. In the art of making carbon black by the partial combustion ofhydrocarbon, the improvement comprising burning hydrocarbon in aplurality of vflames each elongated in one transverse direction, saidllames having their major transverse axes parallel, supplying air tosaid flames suilicient for the complete combustion of between only 45%and 75% of said hydrocarbon and under conditions to cause a steadyupward flow within -the flames of a highly viscous gas envelopecontaining carbon black.

24. The process of producing carbon black which comprises, .burning aplurality of spaced, parallel, flattened streams of ygaseous hydrocarbonin a heat-insulated, enclosed space with an amount of airtheinsuilicient to support complete combust1on of more than 70% of thehydrocarbon, each of the said streams of hydrocarbon having, at itspoint of entrance into the said enclosed space, a transversecrosssectional shape providing a stream approaching the maximumperiphery for a stream of given transverse cross-section.

25. An apparatus for making carbon black by partial combustion ofhydrocarbons, comprising a heat-insulated chamber, a gas conduit in thelower portion of the latter, a plurality of spaced-apart, relativelynarrow gas ducts having their major transverse axis disposed in parallelvertical planes within the chamber and longitudinally thereof, an end ofeach of said ducts means for introducing air into 26. The method ofmakingcarbon black comprising, establishing a plurality ofclosely spacedarallel non-turbulent flowing streams of ydrocarbon gas 1n a com.bustion chamber, establishing and maintaining a thin luminous iiamefront around each of the said gas streams by inclos' the said gasstreams in a uni-directional air stream having a velocity approximatelye ual to that of the gas stream and thereby e ecting diffusion flamecombustion of a part of the said gas, directly transferring la largepart of the heat thus liberated from said iiames by radiation to thebodies of theV as streams behind the flame fronts and iereby eifectingthermal decomposition of a large proportion of the said gas, andpreventing the combustion and deterioration of any substantial amount ofthe free carbon thus formed by rapid removal and cooling of the carbonout of contact with ox gen.

27. Apparatus for the production o carbon black comprising a furnacechamber, a gas burner mounted at one end of the said chamber andconforming closely in contour with the surrounding walls of the saidlchamber adjacent said burner,'rsa'id burner comprising a plurality ofsubstantiall uniformly spaced gas supply ducts 'wit appended burnertips. and air supply ducts disposed around said supply ducts in theinterstitial spaces separatlng the individual gas supply ducts, apredetermined ratio being. maintained between the total cross-sectionalarea of thel gas supply ducts and the total air duct ratio at the iuiddelivery end of the burner.

28. Apparatus for the production of carbon black comprising an elongatedfurnace chamber, a iiuid header within the chamber, a pluralit of spacedfiattened fluid-delivery ducts wit in the chamber, each having one endthereof connected with the said header' 4and each disposed in parallelwith respect to the other ducts and longitudinally of but spaced fromlthe walls of the chamber, each of the ducts being uniform in onecross-sectional dimension throughout their length but being graduallyenlarged in another crosssectional dimension in the directionl away fromthe end connected with the header, means for flowing air into thefurnace chamber adjacent the said header and around and past the saidducts at' a prede- 29. In the 'art of producing carbon black .bythepartial combustion of a hydrocarbon in a heated enclosedfspace, theimprovement comprising, burning natural gas in a plu-` rality of flameseach elon ated in one trans? verse dlrection, the said ames having theirmajor transverseV axes parallel, supplying air to said flames in amountstheoretically sufficient for the complete combustion of about of thesaid natural gas,`the relative velocities of natural gas to the airiiowing into the said enclosed space bein limited `to ratios of between1 2.2 and 1: .6

30. The method of producing carbon black which comprises directing gasand air concurrently in relatively thin sheets into a common combustionchamber, partially burning the gases thereby producing carbon black andcoolin and collecting the resultant carbon blac and other products 0fcombustion.

31. The method of producing carbon 'black which comprises directing asheet of gas in streamline flow into a combustion chamber, directingfinto the combustion chamber a sheet of air in streamline relation withand along each side of the sheet of gas, subjecting the gas to partialcombustion in the combustion chamber thereby producing carbon black, andsubsequently cooling the resultant products andseparating therefrom andcollecting the carbon black.

32. The method ofproducing carbon black which comprises directing asheet of gas-in streamline relation into a chamber los free fromatmospheric disturbance, directing a sheet of air in parallel streamlinerelat1on upon each side of the sheet of gas, partially burning the' gasas it meets the parallelv sheets of air thereby producing carbon black,cooling the gas and collecting products o f combusform streamlinerelation,fdirecting a thin sheetof air iiowing in uniform streamline'relation' upon each side' of the gas sheet,

simultaneously directing the gas and air sheets between parallel wallswhile vsubiecting the gas to' partial combustion thereby producing rcarbon"black, the velocities of the gas and air'being such as to avoidthe development of turbulence, cooling the'gas and sepaiating therefromthe carbonblackpro- 34. The method of producing carbon black which4comprises establishing vertical streamline flow of relativel thinsheets of rounding the respectiven burners, and means gas,`directingsheets of air o in vertifor lindependen y controllin the rate of calstreamline relation upon ca c side of each sheet of gas, partiallyburmn. the gas while maintaining the gas and air ee from atmosphericdisturbance, cooling the .gas and subsequently directing the cooled gasinto collecting receptacles adapted to sepa-- rate carbon black from thecoo ed gas.

35. Apparatus for the roduction of carbon black by partial com ustion ofhydrocarbons, comprising a furnace having therein a burner unit composedof a plurality of spaced burners, the said burners being-relativelynarrow in transverse cross-section and disposed within the furnace so asto have .thelr major cross-sectional axes parallel,

narrow air ducts surrounding the respective burners, the totalcross-sectional area of the burners being substantially less than thetotal transverse cross-sectional area of the said air ducts, each of theburners being provided with a removable burner tip of heat-resistantmetal.

36. A method of producing carbon black which comprises directing gas andair concurrently .in' relatively thin distinct and sub- Y allel wallswhile subjecting thegas to partial 40 combustion, the velocity `of thegas and air being less than that required to produce turbulence,cooling, the products of combustion and segregating the carbon blacktherein contained.

38. The method of producing carbon black which comprises directing arelatively thin sheet of carbonaceous gas within a heated enclosedspace, concurrently directing a. thin' sheet of air surrounding the gassheet within the said space, the respective sheets fluid ow respectivelythroug the burners and thev air ducts.

40. Apparatus for producing carbon black comprising a heating chamber,gas conduits within the said chamber and havin velongated'burner slotsformed therein 1n such manner as to cause gas emitted therefrom .to beejected in substantially parallel sheets,

means for flowing thin streams of airl about the burner slots inparallel relation withresdpect to the ow of gas, and means for inependently regulating the 'rates of iiow of the and the air to reduceturbulence in the owing streams to a minimum.

In testimony whereof I ailix my si ature. DAVID J. BEA ER.

of gas and air liowing in stream line parallel A streams within the saidspace at velocities below that required to produce turbulence,

partially burning the gas thereby producing they said carbon black, andcollecting the latter.

y 39. Apparatus for the production cf carbon black bythe partialcombustion of hydrocarbons, comprising a furnace havin therein a burnerunit composed of a plura ity of spaced elongated burners, the saidburners being relatively narrow in transverse cross-section and disposedwithin the furnace so as to have thelr major cross-sectlonal axesparallel, narrow air ducts sur

